Control apparatus



Allg. 16, 1932. G K SlMONDS 1,871,752

CONTROL APPARATUS Filed Mach 4. 1931 y 7&5 miiygl PatentedY ug. 16, 1932 UNITED STATES GIFFORD K. SIMONDS, 0F BOSTON, IVIASSACHU'SIiiCITS,` .ASSIGNOR TO SIMONDS SAW AND STEEL COMPANY, OF FITCHBURG, MASSACHUSETTS, A CRPO'RATION 0F MASSACHU- SETTS CONTROL APPARATUS Application led March 4, 1931.

or other machining operations in W ich the diameter of the stock is progressively reduced, the optimum speed obviously cannot prevail at each successive diameter unless the speed of rotation is varied in accordance with variations of diameter. v

Accordingly one of the principal objects of the present invention is to improve the eiiiciency of apparatus of this general character by providing means for automatically maintaining the peripheral speed of a rotating piece of stock relative to a tool substantially constant at the optimum speed Vfor the tool irrespective of the diameter of the stock.

The single figure of the drawing is a view illustrating diagrammatically an apparatus for controlling the speed of a piece of stock relative to a tool.

As shown in the drawing a piece of stock 10 is mounted in any usual or approved manner for rotation as by being chucked or otherwise suitably connected to the spindle 11 which is driven by a belt 12 trained over the driving pulley 13 of a driving motor 14. A roller 16 is rotatably mounted upon a rod 17 which is mounted in a bearing 18 to slide in a direction transversely of the stock 10. Preferably this bearing 18 is arranged to guide the roller 16 for movement substantially along a diameter of the stock. The roller 16 is held yieldably in engagement with the periphery of the stock by a coil spring 19 disposed about the rod and interposed between the bearing` and the roller mounting. As the diameter of the stock is reduced by the tool 21, it will be seen that this roller 16 will continue to bear on the periphery of the stock and thus serve as an index of the diameter.

Serial No. 519,992.

Since for a constant rotational speed, the peripheral speed Varies substantially directly as the diameter of the stock, it will be evident that this arrangement provides for ac-V curately and instantaneously controlling the relativev peripheral speed of the stock. In the present instance Vthis control is applied to a variable resistance 22 in the field circuit 23, 24l of the driving motor 14, the rod 17 being connected to an actuating arm 26 which may be mounted to pivot at 27 and thus be capable of varying the resistance and consequently the speed of the motor directly as the diameter and the peripheral speed of the stock changes. v

While the features of the invention have been illustrated as embodied in an apparatus iitted lwith an ordinary turningtool 21, it will beevident that where the tool employed is of the Yrotary or driven type, such as a grinding wheel for example, the relative speed of the stockl and of the rotating tool may be controlled by providing control apparatus of the type illustrated for the tool as well as for the stock being opera-ted upon. Similarly Where a grinding wheel is applied to a substantially flat or plane surface, means of the character illustrated herein for controlling the speed of the stock may be employed for controlling the peripheral speed of the tool.

I claim:

1. In an apparatus of the class describedy wherein the diameter of stock is reduced by a machining operation, means for rotating the stock, means for regulating the speed of rotation thereof, and means continually in contact with the stock for controlling the regulating means whereby the rotation of the stock is automatically maintained continually at the optimum speed.

2. In an apparatus of the class described wherein the diameter of stock is reduced by a machining operation, means for rotating the stock, means for regulating the speed of rotation thereof, means bearing continually against the periphery of the stock during the machining operation, and a connection between said bearing means and said speed regulating means whereby as the peripheral surface of the stock is decreased the speed of the rotation imparted to the stock is relatively increased automatically to maintain the stock continuously at the optimum speed.

3. In an apparatus of the class described wherein the periphery of the stock is reduced by a machining operation7 a motor by which said stock is rotated, a device bearing continually against the periphery of the stock, and means for regulatingl the Speed at which i the Stock is rotated by the motor, said' means including an arm actuated by the device whereby as the periphery of the stock is decreased the speed at Which the stock is rotated by the motor is relatively increased so that the stock is automatically maintained continually at the optimum speed.

4. rlhat method of automatically decreas. ing the speed of rotation of stock in api.- paratus in Which the rotated stock is reduced in. periphery by a machining operation, by

means of a device bearing continually upon the periphery of the-stock..

5'. Means for automatically decreasing' the Speed of rotation of stock in an. apparatus-r` in which the rotated stocglr is reduced in periph ery by a machining operation, comprising a motor by which the stock is rotated, a roller yieldably held continually in Contact with the periphery oi the stock during the machining operation, and a variable resistance by which the speed of the motor is regulated, Said resistance being controlled at all times by the position oisaid roller whereby the stock is maintained at theV optimum speed of' rotation.

Signed by ine at Boston, Mass., this V2nd day of March, 1931.

i GIFFORD K. SIMGND-S. 

